| 1711 Disinfection of cavity preparation using the Er:YAG laser | ||
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C.C. BLAY1, A. BLAY1, J.A. BARROS2, C.D.P. EDUARDO1, and M.C. PETERS2, 1Universidade de Sao Paulo, Brazil, 2University of Michigan, Ann Arbor, USA A great concern for longevity of restorations is the presence of residual bacteria after caries removal, especially in minimally invasive treatment when affected dentin is preserved. The use of lasers for disinfection during endodontic treatment has been widely studied, but data about the antimicrobial effect after cavity preparation is lacking. Objectives: To investigate the disinfecting effect of Er:YAG laser after cavity preparation and conditioning of affected dentin. Methods: Before and after caries removal, affected dentin was sampled from 15 carious molars and premolars and microbiological analysis was performed. After the lesion was accessed by high-speed round bur, a dentin biopsy was taken. The Er:YAG laser (KaVo Key II Laser) was used for cavity preparation and subsequent conditioning of cavity surfaces after caries removal. The Er:YAG laser (2.94 µm) employed the following parameter for cavity preparation: 250 mJ/2Hz, energy density of 62.98 J/cm2. Parameter for surface conditioning (using 50/10 fiber in contact mode) was 60 mJ/10Hz, energy density of 34.68 J/cm2. The pre- and post-preparation dentin biopsies of each tooth were plated and anaerobically incubated for quantitative analysis of bacteria, expressed in colony forming units (CFUs) and qualitative bacterial analysis. Plating assay results were confirmed using polymerase chain reaction technique. Results:All plating assays from carious dentin prior to laser preparation presented a growth of Streptococcus viridans at a minimum level of 100 CFUs, in contrast with complete elimination of residual bacteria after caries removal using the Er:YAG laser. This data suggested that exposure of bacteria to a high-intensity laser resulted in elimination of microorganisms due to photothermic or photoablation effects. Conclusions:The use of Er:YAG laser, within the used parameters, for cavity preparation and conditioning of dentin provided optimal disinfection of the cavity walls prior to restoration. ----- Supported in part by LELO/FOUSP and FAPESP grant # 97/10823-0. | ||
| Seq #194 - Caries Diagnostic, Lasers, Fluorosis 2:00 PM-3:15 PM, Friday, March 23, 2007 Ernest N. Morial Convention Center Exhibit Hall I2-J | ||
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